1. Field of the Invention
The present invention relates generally to housing structures, optical scanning devices, and image forming apparatuses.
2. Description of the Related Art
A typical electrophotographic image forming apparatus forms an image as follows. An optical scanning device optically forms an electrostatic latent image in accordance with image data on an image bearer, such as a photoconductor, uniformly charged in advance. The electrostatic latent image is developed into a visible image with toner by a developing device. The visible image is transferred directly or via an intermediate member, such as an intermediate transfer belt, onto a recording medium such as transfer paper. A fixing device fixes the not-yet-fixed toner image on the recording medium with, for example, a pressure and/or heat. Quality and image quality of the optical scanning device are being enhanced by multi-channeled light-emitting points by adopting a laser diode array (hereinafter, “LDA”), a vertical-cavity surface-emitting laser (hereinafter, “VCSEL”), or the like.
It is already known that fouling of an optical element and the like of such an optical scanning device of an image forming apparatus with dust, a foreign material, or the like can result in an anomalous image (with a white spot or the like).
A configuration for avoiding such a problem by placing a foam material serving as a sealing member in between an optical housing and a cover member covering an opening of the optical housing in a manner to compress the foam material, thereby preventing entry of a foreign material and the like is known. An example of this configuration is disclosed in Japanese Laid-open Patent Application No. 2014-12368.
However, an optical scanning device of an image forming apparatus described in Japanese Laid-open Patent Application No. 2014-12368 is disadvantageous in that because the optical housing compresses the sealing member or an elastic member, deformation of the optical housing occurs, whereby optical characteristics can be degraded. Furthermore, the optical scanning device is disadvantageous in that because it is necessary to impart a complicated shape to the sealing member or the elastic member or divide the sealing member or the elastic member into a plurality of pieces, a sheet material yield undesirably decreases, which leads to an increase in cost.
Therefore, there is a need for a simple housing structure capable of reliably sealing a housing.